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SubjectRe: [Patch v4 02/12] irqchip: axi-intc: Clean up irqdomain argument and read/write
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On 01/09/16 17:50, Zubair Lutfullah Kakakhel wrote:
> The drivers read/write function handling is a bit quirky.
> And the irqmask is passed directly to the handler.
>
> Add a new irqchip struct to pass to the handler and
> cleanup read/write handling.
>
> Signed-off-by: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
>
> ---
> V3 -> V4
> Better error handling for kzalloc
> Erroring out if the axi intc is probed twice as that isn't
> supported
>
> V2 -> V3
> New patch. Cleans up driver structure
> ---
> drivers/irqchip/irq-axi-intc.c | 101 +++++++++++++++++++++++++++--------------
> 1 file changed, 68 insertions(+), 33 deletions(-)
>
> diff --git a/drivers/irqchip/irq-axi-intc.c b/drivers/irqchip/irq-axi-intc.c
> index 90bec7d..7ab0762 100644
> --- a/drivers/irqchip/irq-axi-intc.c
> +++ b/drivers/irqchip/irq-axi-intc.c
> @@ -16,8 +16,6 @@
> #include <linux/io.h>
> #include <linux/bug.h>
>
> -static void __iomem *intc_baseaddr;
> -
> /* No one else should require these constants, so define them locally here. */
> #define ISR 0x00 /* Interrupt Status Register */
> #define IPR 0x04 /* Interrupt Pending Register */
> @@ -31,8 +29,16 @@ static void __iomem *intc_baseaddr;
> #define MER_ME (1<<0)
> #define MER_HIE (1<<1)
>
> -static unsigned int (*read_fn)(void __iomem *);
> -static void (*write_fn)(u32, void __iomem *);
> +struct xintc_irq_chip {
> + void __iomem *base;
> + struct irq_domain *domain;
> + struct irq_chip chip;
> + u32 intr_mask;
> + unsigned int (*read)(void __iomem *iomem);
> + void (*write)(u32 data, void __iomem *iomem);
> +};
> +
> +static struct xintc_irq_chip *xintc_irqc;
>
> static void intc_write32(u32 val, void __iomem *addr)
> {
> @@ -54,6 +60,18 @@ static unsigned int intc_read32_be(void __iomem *addr)
> return ioread32be(addr);
> }
>
> +static inline unsigned int xintc_read(struct xintc_irq_chip *xintc_irqc,
> + int reg)
> +{
> + return xintc_irqc->read(xintc_irqc->base + reg);
> +}
> +
> +static inline void xintc_write(struct xintc_irq_chip *xintc_irqc,
> + int reg, u32 data)
> +{
> + xintc_irqc->write(data, xintc_irqc->base + reg);
> +}
> +
> static void intc_enable_or_unmask(struct irq_data *d)
> {
> unsigned long mask = 1 << d->hwirq;
> @@ -65,21 +83,21 @@ static void intc_enable_or_unmask(struct irq_data *d)
> * acks the irq before calling the interrupt handler
> */
> if (irqd_is_level_type(d))
> - write_fn(mask, intc_baseaddr + IAR);
> + xintc_write(xintc_irqc, IAR, mask);
>
> - write_fn(mask, intc_baseaddr + SIE);
> + xintc_write(xintc_irqc, SIE, mask);
> }
>
> static void intc_disable_or_mask(struct irq_data *d)
> {
> pr_debug("disable: %ld\n", d->hwirq);
> - write_fn(1 << d->hwirq, intc_baseaddr + CIE);
> + xintc_write(xintc_irqc, CIE, 1 << d->hwirq);
> }
>
> static void intc_ack(struct irq_data *d)
> {
> pr_debug("ack: %ld\n", d->hwirq);
> - write_fn(1 << d->hwirq, intc_baseaddr + IAR);
> + xintc_write(xintc_irqc, IAR, 1 << d->hwirq);
> }
>
> static void intc_mask_ack(struct irq_data *d)
> @@ -87,8 +105,8 @@ static void intc_mask_ack(struct irq_data *d)
> unsigned long mask = 1 << d->hwirq;
>
> pr_debug("disable_and_ack: %ld\n", d->hwirq);
> - write_fn(mask, intc_baseaddr + CIE);
> - write_fn(mask, intc_baseaddr + IAR);
> + xintc_write(xintc_irqc, CIE, mask);
> + xintc_write(xintc_irqc, IAR, mask);
> }
>
> static struct irq_chip intc_dev = {
> @@ -105,7 +123,7 @@ unsigned int get_irq(void)
> {
> unsigned int hwirq, irq = -1;
>
> - hwirq = read_fn(intc_baseaddr + IVR);
> + hwirq = xintc_read(xintc_irqc, IVR);
> if (hwirq != -1U)
> irq = irq_find_mapping(root_domain, hwirq);
>
> @@ -116,7 +134,8 @@ unsigned int get_irq(void)
>
> static int xintc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
> {
> - u32 intr_mask = (u32)d->host_data;
> + struct xintc_irq_chip *irqc = d->host_data;
> + u32 intr_mask = irqc->intr_mask;
>
> if (intr_mask & (1 << hw)) {
> irq_set_chip_and_handler_name(irq, &intc_dev,
> @@ -138,59 +157,75 @@ static const struct irq_domain_ops xintc_irq_domain_ops = {
> static int __init xilinx_intc_of_init(struct device_node *intc,
> struct device_node *parent)
> {
> - u32 nr_irq, intr_mask;
> + u32 nr_irq;
> int ret;
> + struct xintc_irq_chip *irqc;
> +
> + irqc = kzalloc(sizeof(*irqc), GFP_KERNEL);
> + if (!irqc)
> + return -ENOMEM;
>
> - intc_baseaddr = of_iomap(intc, 0);
> - BUG_ON(!intc_baseaddr);
> + if (xintc_irqc) {
> + pr_err("%s: Multiple instances of axi_intc aren't supported\n");
> + ret = -EINVAL;
> + goto err_alloc;

How about testing the variable first and error-ing early, rather than
performing the allocation and undoing it later?

> + } else {
> + xintc_irqc = irqc;
> + }
> +
> + irqc->base = of_iomap(intc, 0);
> + BUG_ON(!irqc->base);
>
> ret = of_property_read_u32(intc, "xlnx,num-intr-inputs", &nr_irq);
> if (ret < 0) {
> pr_err("%s: unable to read xlnx,num-intr-inputs\n", __func__);
> - return ret;
> + goto err_alloc;
> }
>
> - ret = of_property_read_u32(intc, "xlnx,kind-of-intr", &intr_mask);
> + ret = of_property_read_u32(intc, "xlnx,kind-of-intr", &irqc->intr_mask);
> if (ret < 0) {
> pr_err("%s: unable to read xlnx,kind-of-intr\n", __func__);
> - return ret;
> + goto err_alloc;
> }
>
> - if (intr_mask >> nr_irq)
> + if (irqc->intr_mask >> nr_irq)
> pr_warn("%s: mismatch in kind-of-intr param\n", __func__);
>
> pr_info("%s: num_irq=%d, edge=0x%x\n",
> - intc->full_name, nr_irq, intr_mask);
> + intc->full_name, nr_irq, irqc->intr_mask);
>
> - write_fn = intc_write32;
> - read_fn = intc_read32;
> + irqc->read = intc_read32;
> + irqc->write = intc_write32;
>
> /*
> * Disable all external interrupts until they are
> * explicity requested.
> */
> - write_fn(0, intc_baseaddr + IER);
> + xintc_write(irqc, IER, 0);
>
> /* Acknowledge any pending interrupts just in case. */
> - write_fn(0xffffffff, intc_baseaddr + IAR);
> + xintc_write(irqc, IAR, 0xffffffff);
>
> /* Turn on the Master Enable. */
> - write_fn(MER_HIE | MER_ME, intc_baseaddr + MER);
> - if (!(read_fn(intc_baseaddr + MER) & (MER_HIE | MER_ME))) {
> - write_fn = intc_write32_be;
> - read_fn = intc_read32_be;
> - write_fn(MER_HIE | MER_ME, intc_baseaddr + MER);
> + xintc_write(irqc, MER, MER_HIE | MER_ME);
> + if (!(xintc_read(irqc, MER) & (MER_HIE | MER_ME))) {
> + irqc->read = intc_read32_be;
> + irqc->write = intc_write32_be;
> + xintc_write(irqc, MER, MER_HIE | MER_ME);
> }
>
> - /* Yeah, okay, casting the intr_mask to a void* is butt-ugly, but I'm
> - * lazy and Michal can clean it up to something nicer when he tests
> - * and commits this patch. ~~gcl */
> root_domain = irq_domain_add_linear(intc, nr_irq, &xintc_irq_domain_ops,
> - (void *)intr_mask);
> + irqc);

What if the domain allocation fails? You've now configured the HW for
something you can't use. What are the side effects? Hint: handle
everything that can fail first, and only then poke the HW.

>
> irq_set_default_host(root_domain);
>
> return 0;
> +
> +err_alloc:
> + xintc_irqc = NULL;
> + kfree(irqc);
> + return ret;
> +
> }
>
> IRQCHIP_DECLARE(xilinx_intc, "xlnx,xps-intc-1.00.a", xilinx_intc_of_init);
>

Instead of posting 3 versions in 3 days, please take the time to
correctly address the comments, and review your own code before
re-posting it. Rushing to get it merged for 4.9 is really not the best
approach.

Thanks,

M.
--
Jazz is not dead. It just smells funny...

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